Photoinduced Electron Transfer on β-Sheet Cyclic Peptides

Conductance of α-Helical Peptides Trapped within Molecular Junctions

“…13 Ghiggino and co-workers observed the different distance dependences for photoinduced electron transfer through R-helical and β-sheet structures and found corresponding decay constants of 0.66 and 0.73 Å -1 , respectively. 14,15 A very weak distance dependence for 3 10 -helices of aminoisobutyric oligomers was reported by Maran and co-workers, who attributed this result to the effect of intramolecular hydrogen bonding on the electron-transfer rate. 16 Kraatz and co-workers also observed a shallow distance dependence of the electrontransfer rate for collagen-like peptide assemblies with interstrand hydrogen bonds.…”

“…Several groups have also demonstrated the influence of the secondary structure of the peptide on electrontransfer efficiency. [13][14][15][16][17] Shin and co-workers showed in their theoretical study that the parameter that describes the ability of the bridge to mediate the electron transfer, i.e., the distance decay constant (β), is sensitive to the secondary structure of the peptide backbone in the case of the superexchange mechanism. 13 Ghiggino and co-workers observed the different distance dependences for photoinduced electron transfer through R-helical and β-sheet structures and found corresponding decay constants of 0.66 and 0.73 Å -1 , respectively.…”

“…For example, upon comparison of the electrochemical data obtained for α-helical peptides, it is evident that the rate constants of electron transfer vary significantly although the lengths of the spacers are similar. , This probably reflects the differences in the details of amino acid sequences. Several groups have also demonstrated the influence of the secondary structure of the peptide on electron-transfer efficiency. − Shin and co-workers showed in their theoretical study that the parameter that describes the ability of the bridge to mediate the electron transfer, i.e., the distance decay constant (β), is sensitive to the secondary structure of the peptide backbone in the case of the superexchange mechanism . Ghiggino and co-workers observed the different distance dependences for photoinduced electron transfer through α-helical and β-sheet structures and found corresponding decay constants of 0.66 and 0.73 Å -1 , respectively. , A very weak distance dependence for 3 10 -helices of aminoisobutyric oligomers was reported by Maran and co-workers, who attributed this result to the effect of intramolecular hydrogen bonding on the electron-transfer rate .…”

A controllable mechanistic transition of charge transfer in helical peptides: from hopping to superexchange

“…Charge transfer in linear 3 10 -helical peptides such as 2 is understood to proceed via a hopping mechanism, 18,48 however very little is known about electron transfer in constrained peptides. 49 Here, Marcus theory 33,50,51 was used in combination with the latest constrained density functional theory (cDFT) 34 to model the diabatic states in 3 10 -helical models 3 and 4 (see Fig. 2a and b) in order to provide an insight into the electron transfer pathway and mechanism(s).…”

Donor–Acceptor Functionalized Luminescent Hairpin Peptides: Electrochemiluminescence of Pyrene/Phenothiazine-Substituted Optically Active Systems

“…[1] Thus, the generation of ECL ranges from different molecular systems [1a,2,3a] and polymers [3] to supramolecular units and nanocrystals. [8] In order to understand the role of peptides and proteins in mediating long-range electron transfer, such studies have yielded valuable results by investigating linear, [9] cyclic, [10] and hairpinshaped [11] peptide systems. [7] Electrochemically generated luminescence produced by nature-related compounds is of interest as a tool for reporting special properties of natural or synthetic systems, and could be suitable for various bioanalytical and optoelectronic appli- cations.…”